Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/12—Packers; Plugs
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
  • E21B33/134—Bridging plugs

Definitions

• the present invention relates to a plug construction comprising an explosive charge as shown in the preamble of the subsequent claim 1.
• explosive charges are placed on the top side of the glass plug. Many mechanisms can be used to activate such explosive charges.
• plugs were used which could be pulled out after use, but later plugs which can be either opened, broken or dissolved after use, have been used.
• NO 321976 describes a test plug of ceramics/glass that comprises an explosive charge and that this explosive charge is placed on the top surface of the plug, approximately as shown in figure 1 (prior art) in the present invention.
• the explosive charge is consequently not arranged inside the plug as is the case for the present invention.
• US patent 5,607,017 describes a core material which shall be dissolved when it comes in contact with well fluid such that the fluid can flow freely.
• the US patent does not describe application of plugs where the explosives are integrated in the plug itself as is the case for the present invention.
• one aims to eliminate, completely or partially, the problems with the unwanted remains from the fitting housing for the explosive charge that come out into the fluid stream and which cause problems for the operator of the field.
• one aims to provide a solution that increases the safety and reduces or eliminates the risk of unintended explosion if one has to apply supporting tools to remove the glass plug because the explosion mechanism fails or does not succeed in blowing the glass plug loose from its seat.
• the plug is characterised in that the explosive charge elements are arranged internally in the plug.
• the plug preferably encompasses a boring that can hold said explosive charge with activation mechanism.
• the plug preferably comprises two or more borings for the placing of a corresponding number of explosive charges with activation mechanisms.
• the new explosive charge works from the inside of the plug element and that one only needs enough explosives to just crush half of the thickness of the glass plug in relation to where the explosive charge is placed on top of the glass plug. Thereby, there is no need for so much explosive material which can thereby be reduced compared to what we required previously.
• the solution according to the present invention is based on standard, off-the- shelf products for the equipment that is required. This makes it possible for the ignitor to be fitted offshore before the fitting in the plug shall take place. Safety wise, this is a better solution and transportation to most production fields becomes easier than for today's solutions.
• the plug system and the trigger system can be pressure tested with no risk of detonation as the
• explosives are installation tested or pressure tested via an opening on the side of the plug.
• the solution according to the present invention functions in that an axial, hydraulic force released by either an electric signal, ultrasound, acoustics or hydraulic pulses in the well is transformed to a radial, mechanical movement which starts the ignition which in turn detonates the explosives lying inside the glass plug.
• Today's systems use an axial hydraulic movement which sets off the ignitor that is also fitted axially on top of the plug element itself.
• the solution according to the present invention does not need its own housing which must be able to withstand pressure up to 800 bar as the plug element itself makes up this housing and protects the explosives against the fluid environment in the well.
• the present solution leads to a very good solution with regard to use of supporting tools to crush the plug as the ignitors and the explosive charges are protected by the plug element, and they will always be exposed to well fluid when the plug element around it is removed. This is a very essential point for the
• the reduced amount of explosives reduces the risk of the plug housing bulging out (ballooning) at the explosion.
• Figure 1 shows a vertical section of a known solution with a glass plug and explosive bodies placed on the top side of the plug.
• Figure 2 shows a vertical section of the new solution according to the invention.
• Figure 3 shows an enlarged detail of figure 2.
• figure 1 illustrates a typical known solution where a plug 20 is fitted inside a pipe bundle 11 which is inserted in a production pipe/casing pipe 10 in the well 30 that runs through a formation 12 in an oil carrying/gas carrying formation.
• the explosive elements in the form of two column-formed bodies 15,16 are placed on the top side 21 of the crushable plug 20 (glass, ceramics or the like).
• the plug 20 hereafter only termed a glass plug, is inserted in the well 30 to carry out pressure testing of the well to control that all parts are sufficiently leak proof and can hold a given pressure of fluid.
• the plug 20 is removed in that it is exploded with the two explosive charges 13,14.
• the explosion can take place in many ways. A normal way is that well fluid, with a given pressure, is let into the inner parts of the explosive charge housing 15,16 so that an ignition pin 19 is pushed down and hits an ignitor 23,17,18 which initiates the ignition of the underlying explosive charge 13,14. The glass is thus burst into a fine dust that does not cause any damage in the well.
• the elements 15,16 themselves are also exploded into small bits. Explosion elements of the type shown in figure 1 , leave several larger fragments in the fluid stream (termed debris) which are not wanted.
• the present invention is characterised in that the explosive element 15 or the elements (15,16) is placed internally in the plug element 20 itself as described in the characteristic in the claim 1 given below.
• the preferred embodiments can be seen in the dependent claims 2-10.
• the present invention is shown in the longitudinally running vertical sections shown in figures 2 and 3, with figure 3 showing an enlarged section of figure 2.
• Figure 2 shows a pipe bundle 10/11 with a glass plug that is inserted in a production pipe/casing pipe in the well 30 that runs through a formation 12 in an oil carrying/gas carrying formation 12.
• a first explosion element 40 is fitted on the one side in the glass plug 20 and a second explosion element 42 on the other side, i.e. the explosion elements 40,42 are diametrically opposite in relation to each other.
• ignition mechanisms are fitted in the outer pipe casing 10 of the plug section that holds the glass plug 21 in its seat, comprising mechanical bodies 50 that cause initiation of the explosion.
• these bodies comprise a downwardly movable, wedge-formed element 50 which is integrated into the pipe casing 10, which is activated to a downward movement in the same way as the constructions inside the explosion elements 15,16 according to figure 1.
• the wedge 50 is held in place in the pipe wall ready for activation of breaking/explosion pins 52.
• Below the wedge 50 there is a hollow space 53 in the pipe that makes the connection to the explosive charge system itself, which is now, according to the invention, fitted in a boring internally in the plug itself.
• the top side of the wedge 50 is connected via fluid with the fluid volume 20 inside the pipe on the top side of the plug.
• An approximately horizontal channel 54 is bored out in the plug 50 and the explosive charge is inserted into this channel, comprising the explosive charge
• the elements are preferably fitted in advance in a closed casing 61 , such as made from plastic or the like, and which is then inserted in the channel 54 in the glass 20. Necessary safeguards that prevent the explosion from happening unintentionally are in place.
• the ignition element 56 (the ignitor) lies consequently between the charge
• the rear end 58 of the ignition pin 57 extends out into the space 53.
• the wedge 50 When the wedge 50 is pushed downwards, it pushes against the rear end of the ignition pin 57 so that the axial movement of the wedge 50 leads to the ignition pin 57 being pushed radially inwards.
• the ignition pin 57 "shoots" thereby into the ignition 56 which then explodes and further detonates the large explosive charge 55 further inside the channel 54. Thus the glass is blown into bits.
• a corresponding explosion system is fitted on the diametrically opposite side in the glass plug, as can be seen in figure 2.
• Several such explosion elements can be fitted if necessary in the glass plug around the whole of the glass plug, for example 3, 4 or more.
• the axial movement of the wedge 50 is activated under the influence of a hydraulic
• the wedge 50 can also be fitted with a spring (not shown) which is held in place with the help of stop-pins, and on activation, the stop-pins become loose so that the spring pushes the wedge 50 downwards with sufficient power to push the ignition pin 57 radially inwards.
• the activation mechanism is divided in two, in that the essential parts such as the ignition pin, the ignitor and the explosive charge are inserted in the glass itself, while the remainder of the activation mechanism is arranged in the outer pipe casing which also comprises the seat 21 of the glass plug.
• the explosive charges are inserted in largely horizontal borings in the glass plug, but they can also be arranged in different inclined positions in the glass plug as required.
• Another great advantage one obtains is when the explosives do not go off and one must install supporting tools to remove the plug. With such a supporting tool the glass plug is often drilled out mechanically.
• the invention represents a much reduced risk for such a drilling operation unintentionally activating an explosion of the charge, as the essential parts of the
• ignition mechanisms is not arranged in the plug but in the pipe casing which is not influenced by the drilling.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Physics & Mathematics (AREA)
• Air Bags (AREA)
• Spark Plugs (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Disintegrating Or Milling (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Taps Or Cocks (AREA)
• Sampling And Sample Adjustment (AREA)
• Examining Or Testing Airtightness (AREA)
• Push-Button Switches (AREA)
• Investigating Or Analysing Biological Materials (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2007
  • 2007-04-17 NO NO20071973A patent/NO329454B1/no unknown
• 2008
  • 2008-04-17 DK DK08753807.0T patent/DK2147188T3/da active
  • 2008-04-17 US US12/450,921 patent/US8397813B2/en active Active
  • 2008-04-17 ES ES08753807T patent/ES2359379T3/es active Active
  • 2008-04-17 AT AT08753807T patent/ATE494453T1/de not_active IP Right Cessation
  • 2008-04-17 EP EP08753807A patent/EP2147188B1/fr active Active
  • 2008-04-17 WO PCT/NO2008/000138 patent/WO2008127126A2/fr active Application Filing
  • 2008-04-17 CA CA2684473A patent/CA2684473C/fr active Active
  • 2008-04-17 DE DE602008004339T patent/DE602008004339D1/de active Active
  • 2008-04-17 BR BRPI0810407A patent/BRPI0810407B1/pt not_active IP Right Cessation

Non-Patent Citations (1)

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